P0606Control Module Processor
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0606 means the module doubts the integrity of its own processor. Checks include a question-and-answer game between main and monitoring processor (GM: new seed via SPI within 450 ms; Ford: 'quizzer' level 3), arithmetic unit and register tests, stack overflow, the order in which safety-critical software runs, and the internal voltage supply (Ford diesel: 5 V rail outside 4.7–5.3 V). Because it belongs to the electronic throttle safety concept, the module usually reacts with a failure mode – reduced power, RPM limit or throttle default position – and the lamp in the first trip. Many cases are software issues fixed by reprogramming (Chrysler 3.6 L 2014, VW Routan, GM brake module 2024), so check bulletins before replacing hardware. The code alone does not say which module set it – the scan tool shows whether it is the engine, transmission, brake or body module.
- What you may notice
- Check engine light, at Ford also the wrench lamp
- Limp mode with reduced power or RPM limit
- Poor throttle response
- Rarely stalling or no start
- Often together with voltage codes P0562/P0563
- Likely causes
- LikelyFaulty module software (update available)
- PossibleLow voltage, voltage dips or a poor ground or supply at the module
- PossibleInternal hardware defect (processor, voltage regulator, output stage chip)
- RareShort on a 5 V sensor reference loading the internal supply
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.